Design And Implementation Of Control System For The Unmanned Agricultural Vehicle

With the implementation of "precision agriculture",the automatic driving technology of agricultural machinery has become a necessary choice to realize modern precision agriculture.By adding sensors and controllers to the traditional hydraulically driven actuators,the satellite positioning and navigation system is used to accurately locate the real-time position of agricultural machinery,thereby achieving the automatic driving function of unmanned agricultural machinery.Aiming at the lack of mechanization of agricultural production and the level of automation in China,this article has designed an unmanned tractor control system based on RTK-GPS navigation and positioning.The specific research work can be divided into the following parts:(1)The research background and significance of the subject are first introduced,and the current research status of unmanned agricultural machinery at home and abroad,and the development status of navigation and positioning methods and path tracking control are described.(2)Secondly,the mechanical transformation and circuit design of the unmanned agricultural machine control system experimental platform are introduced.This design is based on the Tianjin Tieniu tractor,and through its mechanical and electrical transformation,it forms an unmanned agricultural machine experimental platform.The lower computer uses STM32F103 as the main control chip,and realizes the communication between the upper computer and the lower computer,and the RTK-GPS and the controller through the wireless data transmission module,so as to implement the unmanned real-time control of the agricultural machinery execution mechanism through the path tracking control algorithm.(3)The automatic navigation control algorithm of unmanned agricultural machinery is analyzed,and the angular loop fuzzy PID control algorithm and the speed loop incremental PID control algorithm are proposed respectively in combination with the actual working characteristics of unmanned agricultural machinery.The feasibility of the path tracking control algorithm is verified by simulation and experiments.(4)Finally,the experiments of unmanned agricultural machinery on simulated roads are introduced,the operation process is explained,and the experimental results are analyzed.After experimental verification,when the speed of the agricultural machine is 0.55 m / s,the maximum error of linear path tracking is 4.09 cm,the average error is 2.20 cm,the maximum error of large diameter circular path tracking is 20.67 cm,the average error is 8.34 cm,and the maximum error of continuous small diameter turning path tracking is 23.14 cm,with an average error of 7.38 cm,all meet the operational requirements,which proves the feasibility of the unmanned agricultural machinery control system.